Yes, definitely gibberish. When I was a boy sprout in the 1950s it amused us 'orrible small boys that naive leaders (and B-P!)didn't realise that Goolies was slang for testicles. It was more popular than B-P's attempts at getting scouts to sing Zulu chants from his army days like Eengonyama. It was sung as a round as a change from Frere Jaques or London's burning. We boys preferred Oggy Oggy Oggy, Oy oy Oy which pitted one side against the other for volume rather than musical ability- a quality that has sadly informed my subsequent attempts to sing!

RtS